Refrigerating apparatus



Filed June 24. 1954 INVENTOR. John Do/za His Aflorney United StatesPatent REFRIGERATING APPARATUS John Dolza, Davisburg, Mich., assignor toGeneral Motors Corporation, Detroit, Mich., a corporation of Delta ware.

Application June 24, 1954, Serial No. 438,986 1 Claim. (Cl. 230-186)This invention relates to refrigerating apparatus and more particularlyto an improved type of refrigerant compressor.

It is an object of this invention to provide an improved low costbearing arrangement for an axial compressor. More particularly it is anobject of this invention to provide an improved type of low cost endthrust bearing for the wobble plate element of an axial compressor.

Still another object of this invention is to provide an improved oilhandling arrangement for an axial type multiple cylinder compressor.

A further object of this invention is to provide an improved compressorhousing which may be manufactured at a low cost and which facilitatesaligning the various bearing surfaces.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Figure l is a vertical sectional view of a compressor embodying theinvention; and,

Figure 2 is a sectional view taken substantially on line 22 of Figure 1.

Referring now to the drawings wherein a preferred embodiment of theinvention has been shown, reference numeral designates the main casingwhich is made of sheet metal so as to reduce both the cost and weight ofthe compressor. A main shaft 12 is provided as shown and is supportedfor rotation within the casing 10 with one end of the shaft projectingthrough the casing so as to receive a drive pulley (not shown) for usein driving the compressor. The shaft12 has its one end journalled in acylinder block 14 and has its other end journalled in a bearing block16. The bearing block 16 has a press fit within the reduced or neckportion 18 of the sheet metal casing 10. A bearing element 20 isprovided as shown which has a press fit on the drive shaft 12. Thecylinder block 14 is provided with a beveled surface 22 which fits upagainst a complementary beveled surface 24 provided on the casing 10.The beveled surface 24 is made concentric, to the inner surface of theneck portion 18 so as to facilitate accurate alignment between the frontand rear bearing surfaces for the drive shaft 12. i

It will be noted that the drive shaft has been made straight and that acast bearing element 26 has been pressed onto the midportion of theshaft so as to rotate with the shaft and form a support for the wobbleplate 39. A plurality of connecting rods 32 drivingly connect the wobbleplate with a plurality of pistons 34 which operate within bores 36provided in the cylinder block 14. For purposes of illustration, afive-cylinder compressor has been shown whereas the number of cylindersmay be varied without departing from the spirit of the invention.

r 2,868,443 Patented Jan. 13, 1959 The end thrust on the wobble plateas: a result of the operation of the compressor is taken up by a stampedsheet metal end thrust bearing 40 which is attached to the bearing block16. The end thrust bearing 40 is cup-shaped with the rim of the cupbeveled as at 42 to engage the spherical bearingsurface44 on the wobbleplate 30L The refrigerant to be compressed enters the housing 10 throughthe suction line 60 which communicates with a central suction chamber 62at the head end of the cylinder block 14. A vent passage 64 has beenprovided as shown for equalizing the pressure within the main crankcase63 and the chamber 62 with the result that the crankcase of thecompressor which serves as an oil sump is maintained at a pressurecorresponding substantially to the low side pressure of the refrigerantsystem. A valve plate 66 has been provided as shown and includes theusual inlet and outlet ports 65 and 67 respectively communicating withthe ends of the compression chambers. The compressed refrigerantdischarges through the usual outlet ports 67 into an outlet chamber 68provided in surrounding relationship to the suction chamber 62. Thechambers 62 and 68 are separated from one another by the insert element69 which is held in place by the end wall 71 of the main casing 10. Asshown in Figure l, the element 69 abuts against the valve plate 66 whichin turn abuts against the cylinder block 14 so as to hold the bevelledsurfaces 22 and 24 in firm contact with one another. The end wall 71 isbrazed to the casing 10 at 73 along its outer periphery. The compressedrefrigerant leaves the chamber 68 through the usual high side line 70which would lead to the condenser (not shown) of a refrigerating system.

A conventional shaft seal generally designated by the reference numeral72 has been provided for preventing the escape of lubricant and/orrefrigerant at the point which the shaft projects through the end of thehousing 10. A conventional oil pump 74 is provided as shown and servesto withdraw oil from the bottom of oil sump through the inlet tube 75and to discharge the oil directly into the shaft seal cavity 76 fromwhence a portion of the oil fiows under pressure through oil passages 77and 79 into the space 78 provided between the spherical portion of thewobble plate 30 and the end thrust bearing 40 so as to force lubricantto How outwardly between the rim of the end thrust bearing 40 and thewobble plate. By virtue of this construction, the wobble plate in effectfloats on a film of oil with the result that the friction losses aremaintained at a minimum. A portion of the oil enters a passage 80 in theshaft through a radial passage 81 and then flows through a radiallyextending passage 82 to the rear shaft bearing 84. Some of the excessoil leaving the rear bearing 84 feeds back into the suction chamber 62where it is picked up by the refrigerant entering the suction ports ofthe various compression chambers so as to lubricate the pistons of thecompressor. Much of the oil handled by the pump 74 will of course bereturned to the crankcase as it escapes from the various bearingsurfaces for the shaft 10 and the wobble plate assembly.

In acordance with the provisions of rule 78a, reference is made to thefollowing prior filed applications: Serial No. 347,556, filed April 8,1953, and Serial No. 398,319, filed December 15, 1953, now Patent No. 2,798,663.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, as may come within the scope of the claim whichfollows.

What is claimed is as follows:

In an axial type of compressor, a stamped sheet metal housing having acircular portion provided with an in ice 3 ternal beveled surfaceadjacent its one end and and having a reduced cylindrical neck portionadjacent its opposite end, a bearing insert having a press fit withinsaid neck portion, a cylinder block having a beveled surfacecomplementary to said first named beveled surface, said cylinder blockbeing shiftable sideways relative to the axis of said circular portionin response to engagement of said complementary beveled surface, abearing aperture in said block concentric to said beveled surface, acompressor shaft having its one end journalled in said bearing apertureand having its other end journalled in said bearing insert, and meansfor holding said beveled surfaces in firm contact with one another, awobble plate mechanism operated by said shaft, and an end thrust bearingfor said wobble plate mechanism carried by said bearing insert.

References Cited in the file of this patent UNITED STATES PATENTS1,418,951 Martin June 6, 1922 2,062,035 McCormack Nov. 24, 19362,106,236 Burke Jan. 25, 1938 2,329,912 Kent Sept. 21, 1943 2,365,309Talbot Dec. 19, 1944 2,405,938 Beck Aug. 20, 1946 2,433,222 Huber Dec.23, 1947 2,492,688 Dall Dec. 27, 1949 2,570,698 1951 Manseau Oct. 9,

